Accumulating evidences suggest that aldose reductase (AR) inhibitors and advanced glycation end product (AGE) formation inhibitors may prevent chronic hyperglycemia-induced long-term complication in diabetes. Transforming growth factor-beta1 (TGF-β1) plays an important role in the development of diabetic nephropathy. Allium species have been utilized in folk medicine throughout the world for the treatment of various physical disorders. However, the benefits of Allium victorialis (A. victorialis) against diabetic complications, especially nephropathy, have yet to be explored. In the present study, we investigated the protective effect of the compounds isolated from A. victorialis leaf on diabetic nephropathy. In vitro AR activity, AGEs formation, and AGE-receptor for AGEs (RAGE) binding in human RAGE (hRAGE)-overexpressing cells were tested. High glucose-induced transforming growth factor-beta1 (TGF-β1) expression was also examined in mouse kidney mesangial cells (MMCs) cultured under high glucose. Of the isolated eight compounds from A. victorialis leaf extracts tested, quercitrin exhibited the most pronounced inhibitory effects on AR activity (IC50 value of 0.17 μM) and AGEs formation (IC50 value of 4.20 μM). Furthermore, quercitrin disrupted AGE-RAGE binding in a concentration-dependent manner in hRAGE-overexpressing cells. Additionally, of the eight compounds tested, ferulic acid significantly reduced high glucose-induced TGF-β1 expression and secretion in MMCs. Our results suggest that active compounds isolated from A. victorialis leaf exhibit inhibitory effects on AR activity in rat lenses and AGE formation. Further, ferulic acid reduces TGF-β1 mRNA expression and secretion in MMCs under diabetic conditions. Thus, A. victorialis is a good candidate for the development of treatments for diabetic nephropathy.

Background. Pueraria lobata is used in traditional Asian medicine to treat cardiovascular diseases, diarrhea, diabetes mellitus, and diabetic complications such as diabetic retinopathy. Oxidative stress in retinal pigment epithelial cells is implicated in the pathogenesis of retinopathy and age-related macular degeneration (AMD). Here, we evaluated whether the P. lobata extract can prevent cell death and decrease membrane permeability in oxidative stress-induced human retinal pigment epithelial cells. Methods. The effects of P. lobata extract on hydrogen peroxide- (H₂O₂-) induced oxidative stress were investigated using 2′,7′–dichlorofluorescin diacetate, western blotting, and immunohistochemistry in human retinal pigment epithelial cells. The effects of puerarin, daidzein, and daidzin isolated from P. lobata extract were also studied by determining cell death, reactive oxygen species (ROS) generation, and p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) phosphorylation. Results. Our results showed that the P. lobata extract inhibited ROS generation, suppressed the disruption of zonula occludens-1 (ZO-1), and reduced membrane permeability in H₂O₂-induced human retinal pigment epithelial cells. Additionally, the P. lobata extract prevented the inhibition of p38 MAPK and JNK phosphorylation. Conclusion. Our findings suggest that the P. lobata extract has the potential to prevent AMD development by inhibiting the mechanism underlying oxidative stress-mediated ocular disorders.

Oxidative stress is a major contributor to muscle aging and loss of muscle tissue. Jakyakgamcho-tang (JGT) has been used in traditional Eastern medicine to treat muscle pain. Here, we compared the total phenolic and flavonoid contents in 30% ethanol and water extracts of JGT and tested the preventive effects against oxidative stress (hydrogen peroxide)-induced cell death in murine C2C12 skeletal muscle cells. The total phenolic content and total flavonoid content in 30% ethanol extracts of JGT were higher than those of water extracts of JGT. Ethanol extracts of JGT (JGT-E) had stronger antioxidant activities of 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2′-diphenyl-1-picrylhydrazyl-scavenging activity (DPPH) than water extracts of JGT (JGT-W). JGT-E contained 19–53% (1.8 to 4.9-fold) more active compounds (i.e., albiflorin, liquiritin, pentagalloylglucose, isoliquiritin apioside, isoliquiritin, liquiritigenin, and glycyrrhizin) than JGT-W. The ethanol extracts of JGT inhibited hydrogen peroxide-induced cell death and intracellular reactive oxygen species generation more effectively than the water extract of JGT in a dose-dependent manner. For the first time, these results suggest that ethanol extract of JGT is relatively more efficacious at protecting against oxidative stress-induced muscle cell death.

Age-related ocular diseases such as age-related macular degeneration, glaucoma, and diabetic retinopathy are major causes of irreversible vision impairment in the elderly. Conventional treatments focus on symptom relief and disease slowdown, often involving surgery, but fall short of providing a cure, leading to substantial vision loss. Regenerative medicine, particularly mesenchymal stem cells (MSCs), holds promise for ocular disease treatment. This study investigates the synergistic potential of combining placenta-derived MSCs (PD-MSCs) with Achyranthis radix extract (ARE) from Achyranthes japonica to enhance therapeutic outcomes. In a 24-h treatment, ARE significantly increased the proliferative capacity of PD-MSCs and delayed their senescence (* p < 0.05). ARE also enhanced antioxidant capabilities and increased the expression of regeneration-associated genes in an in vitro injured model using chemical damages on human retinal pigment epithelial cell line (ARPE-19) (* p < 0.05). These results suggest that ARE-primed PD-MSC have the capability to enhance the activation of genes associated with regeneration in the injured eye via increasing antioxidant properties. Taken together, these findings support the conclusion that ARE-primed PD-MSC may serve as an enhanced source for stem cell-based therapy in ocular diseases.

Retinal apoptosis plays a critical role in the progression of diabetic retinopathy (DR), a common diabetic complication. Currently, the tight control of blood glucose levels is the standard approach to prevent or delay the progression of DR. However, prevalence of DR among diabetic patients remains high. Focusing on natural nutrients or herbal medicines that can prevent or delay the onset of diabetic complications, we administered an ethanol extract of the aerial portion of Osteomeles schwerinae (OSSCE), a Chinese herbal medicine, over a period of 17 weeks to spontaneously diabetic Torii (SDT) rats. OSSCE was found to ameliorate retinal apoptosis through the regulation of advanced glycation end product (AGE) accumulation, oxidative stress, and mitochondrial function via the inhibition of NF-κB activity, in turn, through the downregulation of PKCδ, P47phox, and ERK1/2. We further demonstrated in 25 mM glucose-treated human retinal microvascular endothelial cells (HRMECs) that hyperoside (3-O-galactoside-quercetin), quercitrin (3-O-rhamnoside-quercetin), and 2″-O-acetylvitexin (8-C-(2″-O-acetyl-glucoside)-apigenin) were the active components of OSSCE that mediated its pharmacological action. Our results provide evidence that OSSCE is a powerful agent that may directly mediate a delay in the development or disease improvement in patients of DR.